Search PubMed⌕ Search

Biomedical subjects

L Lowenstein

Publications and source records attributed to L Lowenstein.

At least 19 recordsLinked to original sources
PubMed2006

Urinary hesitancy and retention during treatment with sertraline.

We report the cases of two women who began to experience urinary hesitancy and retention after starting treatment with sertraline for depression. Discontinuation of the drug resulted in complete symptom relief. Serotonergic neurons are involved at several levels in control of the lower urinary tract. Retention is apparently an uncommon complication of sertraline. Discontinuation should be considered for patients presenting with voiding difficulties.

Aged↗
PubMed2006

Pre-eclampsia is associated with sleep-disordered breathing and endothelial dysfunction.

Pre-eclamptic toxaemia (PET) may be associated with both endothelial dysfunction (ED) and sleep-disordered breathing (SDB). It was hypothesised that females with PET would demonstrate both SDB and ED, and that a correlation between these two would suggest a potential causative association. A total of 17 females with PET and 25 matched females with uncomplicated pregnancy were studied. They underwent a nocturnal ambulatory sleep study (using Watch_PAT100) and noninvasive evaluation of endothelial function utilising the reactive hyperaemia test (using Endo_PAT 2000). A higher ratio of post- to pre-occlusion pulse-wave amplitude (endothelial function index (EFI)) indicated better endothelial function. Females with PET had a significantly higher respiratory disturbance index (RDI) and lower EFI than controls (18.4+/-8.4 versus 8.3+/-1.3.h(-1), and 1.5+/-0.1 versus 1.8+/-0.1, respectively). Blood pressure significantly correlated with RDI and with EFI. EFI tended to correlate with RDI. In conclusion, these results suggest that both sleep-disordered breathing and endothelial dysfunction are more likely to occur in females with pre-eclamptic toxaemia than in females with uncomplicated pregnancies. The current authors speculate that respiratory disturbances contribute to the functional abnormality of the blood vessels seen in females with pre-eclamptic toxaemia, although causality cannot be determined based on this study.

Adult↗
PubMed2000

[Transient ischemic ECG changes in a patient with acute cholecystitis without a history of ischemic heart disease].

That abdominal distention, nausea, and chest pain may be accompanied by ischemic ECG changes is well known and has been described in the literature. However, very few cases have been reported with acute cholecystitis and ECG changes not due to cardiac ischemia. We present a previously healthy 20-year-old woman admitted with acute cholecystitis. Prior to surgery routine ECG showed ST-depression and T-wave inversion. The day following cholecystectomy the ECG returned to normal. 1 month later, ergometry and echocardiography were both negative. Based on the literature and our personal experience, although ECG changes may occur in acute cholecystitis, the possibility of cardiac ischemia must be excluded. However, when no cardiac basis is found, ultrasound of the biliary system might reveal the cause of these ECG changes. Thus, in acute cholecystitis with ischemic ECG changes but no other laboratory or clinical evidence of cardiac ischemia, ECG changes alone are not a contraindication to cholecystectomy. Furthermore, delay in treatment could be harmful.

Adult↗
PubMed1999

Rapid estimation of the accuracy of automatic blood pressure measuring devices (READ).

We propose a rapid method for the evaluation of automatic blood pressure measurement devices (READ) in response to the claim to simplify the validation of those devices. The READ is based on numerous blood pressure (BP) measurements at rest and during a standardised postural challenge in a small number of subjects who exhibit a wide range of BPs. Automatic (AU) and mercury sphygmomanometric (MS) brachial BP were measured simultaneously in a blinded manner. An average of 30 measurements per patient were done in 10-min while in a supine position, followed by 30 min in head-up tilt and again supine for 10 min. Two Collin-8800 automated oscillometric devices were tested with the aid of the READ in 15 adults. The consistency of the MS standard was demonstrated by duplicate MS measurements showing minimal inter-observer differences consistent with class A of the British Hypertension Society (BHS) grading system. AU-to-MS differences of 447 measurements were mean systolic deltaBP = 1.1 +/- 11.4 mm Hg and mean diastolic deltaBP = -13.36 +/- 8.9 mm Hg, classifying into category D of the BHS. Both tested instruments, each subject, each phase of the tilt test (supine I, tilt, supine II) and each mode of measurement (at 5-min intervals or continuously) equally qualified as 'D'. We conclude that the READ permitted us to identify quickly and at low expense a grossly inaccurate automatic BP measuring device. Further studies will show whether the READ can be efficient as a pre-validation test, post-validation test, and for assessment of ambulatory BP measuring devices.

Adult↗
PubMed1979

Evolution of polypyrimidines in Drosophila.

We surveyed 101 different Drosophila species for the presence of a particular highly repetitive DNA sequence containing long tracts of polypyrimidine/polypurine DNA, first found in D. melanogaster. Out of 55 tested species in the melanogaster group, only the sibling species D. simulans and D. mauritiana, as well as one distant relative in the ananassae subgroup, D. varians, contained the same sequence. All four of these species have long pyrimidine tracts as shown by acid hydrolysis of labelled DNA. All four species have the same sequence, bu the amount of this polypyrimidine/polypurine DNA varies greatly. Four other species in the hydei subgroup were found to contain a polypyrimidine/polpurine sequence, with an oligonucleotide composition different from that of D. melanogaster. This polypyrimidine DNA varies from as much as 10% of the total DNA in D. nigrohydei, to as little as 0.4% in D. neohydei. The long pyrimidine tracts in the hydei subgroup are often more than a thousand nucleotides in length, representing exceedingly homogeneous repetitious sequences.--These results show a rapid but discontinuous pattern of evolution for polypyrimidine/polypurine DNA . These sequences are not species specific, yet closely related species have greatly different amounts of polypyrimidines. Drastic changes occur in the amounts of these satellite type DNA sequences, as if the sequence had no continuous selective advantage in evolution. The implications of these results with regard to the general function and evolution of satellite DNA are discussed.

Animals↗
PubMed1975

Polypyrimidine segments in Drosophila melanogaster DNA: II. Chromosome location and nucleotide sequence.

Long pyrimidine tracts, purified from Drosophila melanogaster DNA after treatment with formic acid-diphenylamine, were used as template for E. coli RNA polymerase to produce a polynucleotide containing only purines. This polypurine RNA hybridized specifically to D. melanogaster DNA with high efficiency at low Cot values. The resulting hybrid showed high thermal stability. When polypurine RNA was subjected to complete hydrolysis with ribonuclease T1, over 90% of the nucleotide products were ApGp and ApApGp. Partial hydrolysis yielded a distinct additional component, ApApGpApGp + ApGpApApGp. We conclude that the major sequence in the polypurine transcript is (ApGpApApGp)n. In situ hybridization to salivary gland polytene chromosomes and to metaphase chromosomes from neural ganglia indicated that polypyrimidines complementary to polypurine RNA are located in heterochromatin. In femal cells, the predominant labeling was on centromeric heterochromatin of the 2nd chromosome. We have verified the location of polypyrimidines in neural ganglion cells, by using a cytological marker of chromosomes 2. In male cells, hybrid was also found on the Y chromosome.

Adenosine Triphosphate↗
PubMed1975

Acid treatment of Drosophila deoxyribonucleic acid.

In cytologic preparations of chromosomes, acid-treated deoxyribonucleic acid (DNA) is found largely in the native state. However, acid treatments widely used for chromosome preparations produce significant amounts of depurination in DNA. DNA is similarly sensitive to depurination in intact cells or as purified DNA. If treated with alkali, these apurinic gaps can be converted to single strand breaks. Acid treatment has widely different effects on specific fractions of DNA. In Drosophila melanogaster 3% of the DNA is composed of very long tracts of pyrimidines (polypyrimidines) which are resistant to acid hydrolysis. The implications of these results for molecular cytogenetics are discussed.

Acetates↗